Such a method is disclosed in U.S. Pat. No. 5,725,163, and protects to some extent the crusher from excessive loads that may damage different parts of the crusher when a high-density tramp iron object such as an excavator tooth or a grinding ball enters the crusher. However, just slightly increasing the crusher gap will in most cases not be sufficient to remove the high-density object. This means that the crusher will experience a number of further impacts when attempting to crush the high density object during further gyrations. The combined effect of such further impacts may still damage the crusher shells or other parts of the crusher.